All Chinese boats illegally fishing in the neutral waters near the Han River's estuary between the two Koreas have left the area after the South Korean military kicked off a crackdown operation late last week, the defense ministry said Thursday.

"Currently, there are no Chinese boats in the neutral waters in the estuary area," Moon Sang-gyun, the Ministry of National Defense's spokesman, said in a regular briefing.

"But our military is ready to resume its crackdown because the illegal fishing could resume anytime," Moon noted.

Under the authorization of the United Nations Command, which regulates the military buffer zone, the military kicked off the operation to drive out Chinese fishing boats in the area starting on Friday.

Four speed boats and a 24-man military police team have been sent to the neutral waters which had seen a sharp increase in Chinese fishing vessels illegally trespassing upon the no man's land to catch blue crabs.

On Tuesday evening, the crackdown team seized two Chinese vessels and their crews and turned them over to the Coast Guard.

The latest operation is the first crackdown on illegal fishing in waters where the Han River flows into the Yellow Sea after the region was declared neutral in the 1953 armistice between the two Koreas.

South Korea has vowed to eject all Chinese fishing boats and even called on Beijing to do its part to prevent its fishermen from venturing into the tension-ridden area. (Yonhap)